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Abstract: FR-PO557

Identification of Paracrine Factors in the Early Cyst Microenvironment in Polycystic Kidney Disease

Session Information

Category: Genetic Diseases of the Kidneys

  • 1201 Genetic Diseases of the Kidneys: Cystic

Authors

  • Yasinoglu, Sevtap Aysu, Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
  • Kuipers, Thomas B., Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
  • Bange, Hester, Crown Bioscience Netherlands B.V., Leiden, Netherlands
  • Eikmans, Michael, Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
  • Mei, Hailiang, Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
  • Baelde, Hans J., Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
  • Peters, Dorien J.M., Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
Background

Initial cysts that are formed upon Pkd1 loss in mice impose persistent stress on surrounding tissue and trigger a cystic snowball effect, leading to the activation of PKD-related signaling which increases the likelihood of new cyst formation and disease progression. In the present study, we profiled transcriptomic changes that occur in the cyst microenvironment in PKD mice and identified paracrine factors with increased activity in PKD mice and in human ADPKD cyst cultures.

Methods

To perform an unbiased analysis of transcriptomic alterations that occur in the cyst microenvironment, microdomains were collected from iKsp-Pkd1del mice with scattered Pkd1-deletion using Laser Capture Microdissection. Based on F4/80 staining, collected microdomains were defined as either macrophage (MΦ)-low cystic, representing early alterations in the cyst microenvironment, MΦ-high cystic, with more advanced alterations, or non-cystic. Pathway and upstream regulator analyses were applied to identify dysregulated pathways and secreted factors that may play a key role in altered signaling. Finally, supernatants from 3D cultures of primary ADPKD cells were harvested to analyze secreted paracrine factors using a Bio-Plex assay.

Results

When compared to the non-cystic microdomains, 953 and 8088 genes were dysregulated in MΦ-low and MΦ-high regions, respectively. Several injury-repair, growth, and tissue remodeling-related pathways were activated in MΦ-low microdomains, accompanied by mild metabolic alterations. In the more advanced MΦ-high microdomains, these pathways were strongly potentiated and the metabolism was more dysregulated. Using upstream regulator analysis, paracrine factors were identified with increased activity in the early cyst microenvironment, including IFNG, TNF, IL1B, TGFB1, AGT, and PDGFB. In addition, we identified TNF-α, PDGF-β, and several other factors that were secreted by primary ADPKD cells in the culture medium.

Conclusion

Collectively, our data provide an overview of molecular alterations that occur specifically in the MΦ-low and MΦ-high cyst microenvironment. Also, paracrine factors were identified that may drive early epithelial cell-induced alterations and tissue remodeling, which potentially give rise to the formation of more cysts.

Funding

  • Private Foundation Support